I think the flaw in this theory relies on a fundamental assumption: WotC knows what is balanced. I honestly don't think they do.

Look at Wizard. Now look at Fighter. Notice how they're both core. Notice how WotC thought core was balanced. Realize that WotC doesn't really get 3.5 balance. Yes, they fixed evertyhing in 4.0, but they really didn't 'get' balance in 3.5. They created whatever they wanted from a fluff perspective and did only minimal balancing.

Because WotC doesn't really understand balance, they print both Shadowcraft Mage and Green Star Adept. They print both Ninja and Archivist. They don't really get it.